Gristmill with automatic shut-off



2 Sheets-Sheet 1 Filed March 22, 1967 y 1969 c. LENZ 3,458,141

GRISTMILL WITH AUTOMATIC SHUT-OFF Filed March 22, 1967 2 Sheets-Sheet z //v l/E/V TOR M M w United States Patent Int. Cl. BilZc 4/06 US. Cl. 241-36 9 Claims ABSTRACT OF THE DISCLOSURE A gristmill having crushing rollers and a malt bin mounted on a mill housing which partly constitutes the supporting structure of the mill and is mounted on a foundation frame partly by rigid load transmitting elements and partly by means of a resilient horizontal bar whose ends are fastened to the supporting structure while columns on the foundation engage a central portion of the bar. The bar is resiliently deformed by the weight of the mill housing and of the mass supported thereon, and opens a switch in the circuit of the electric drive motor of the crushing rollers when relieved of the weight.

Background of the invention This invention relates to brewery equipment and par ticularly to a gristmill and to shut-off controls for the drive motor of the mill.

Wet milling is normally a batch operation, and the operating economy of the mill is affected to a substantial extent by proper utilization of working time. The mill should be shut off, cleaned, and prepared for the next batch as soon as milling of the preceding batch is completed.

If the judgment of an operator is relied upon for stopping the crushing rollers of the mill and for initiating the necessary steps preparatory to the processing of the next batch, human error may result in substantial losses of operating time. Moreover, the time of an operator can be utilized otherwise to better advantage.

The object of the invention is the provision of a gristmill which stops automatically as soon as a batch of malt has been milled.

Summary of the invention The invention resides mainly in an improvement of a gristmill which may otherwise be conventional, and includes a mill housing, a pair of crushing rollers mounted in the housing and driven by a motor, a malt bin, and malt feeding mechanism for feeding malt from the bin to the housing. The mill housing is a part of the supporting structure of the mill and is itself supported on a foundation.

According to this invention, resilient load transmitting means are interposed between the aforementioned supporting structure and the foundation for transmitting to the foundation a portion of the weight of the supporting structure and of the mass supported thereon. The resilient load transmitting means include :a load transmitting member, such as a bar, which is resiliently deformable in response to the transmitted weight, and there is further provided a control operating mechanism which may be engaged by the deformed load transmitting member and is operatively connected to the motor controls for rotating and stopping the rollers in response to deformation of the load transmitting member under an applied weight, and in response to the resilient recovery of the member when released of the applied weight.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing.

Brief description of the drawing In the drawing:

FIG. 1 shows a gristmill of the invention in side elevation and partly in section;

FIG. 2 shows a portion of the apparatus of FIG. 1 in side elevation on a larger scale; and

FIG. 3 shows the device of FIG. 2 in section on the line IIIIII in FIG. 1.

Description of the preferred embodiment Referring now to the drawing in detail, and initially to FIG. 1, there is seen a largely conventional gristmill whose malt bin 2 tapers downwardly to a bottom flange 4 fixedly mounted on a mill housing 6 by means of a flange 8 at the top of the housing 6 and by a flanged rotary drum feeder 10, not shown in detail, interposed between the flanges 4 and 8. Two crushing rollers 12 are journaled in the housing 6 and are driven by an electric motor 72 through a gear transmission 74 having two output shafts. The rollers 12 rotates in opposite directions, as is usual. The motor 72 is connected to a source of electric current, not itself shown, through a control circuit which includes a cable 70 and a control assembly 68, more fully described hereinafter.

The housing 6 is a fixed part of the mill support which also includes an upright frame 26. The housing 22 of a rotary mash pump 14 is attached to the frame 26, the housing 6 conically tapering downward toward the intake of the pump. The pump 14 discharges into a conduit 24 which leads to a mash copper, not itself illustrated.

A water line 16 leads into the housing 6 for providing water to be mixed with the crushed malt, the stream of water discharged from the line 16 being dispersed by a horizontal distributor plate 18 mounted on a vertical extension 20 of the pump shaft. The pump 14 is driven by an electric motor by means of a belt, not shown.

The lower part of the supporting structure and of the foundation of the gristmill is shown in more detail in FIGS. 2 and 3. FIG. 3 shows only one half of the apparatus of FIG. 1, the non-illustrated half being symmetrical with the illustrated portion relative to a plane of symmetry S--S except as stated below.

The upright frame 26 is welded to the mill housing 6 at the top and to a rectangular horizontal frame 28 of L- section bars at the bottom. The frame 26 partly consists of upright sheet metal webs 48. The supporting structure of the mill is carried by a foundation which includes a rectangular horizontal frame 30 assembled from steel channels by welding, a ground plate 32 interposed between the ground or a building floor and the foundation frame 30, and bolts 34 which fasten the foundation to the ground or floor. Bolts 36, of which only one is seen in FIG. 2, fasten the support frame 28 to the foundation frame 30 along one side of each frame.

The opposite sides of the frames 28, 30 are normally vertically spaced from each other. The foundation frame 30 carries two short upright columns 38 of which only one is seen in the drawing. The column has an internally threaded base block 40 threadedly receiving a spindle 42 which may be axially adjusted in the block 40, and fixed in the adjusted position by a locking nut 44. A bearing shell 46 is attached to the top of the spindle 42. The shell 46 provides a conforming, upwardly open receptacle for a hollow cylindrical bar 50 whose terminal portions 52 are rotatably received in respective openings of the sheet metal webs 48, and secured against rotation by annular clamps 54 having radial lugs 56 received in retaining forks 58 on the associated webs 48.

The bar 50 thus extends along the sides of the frames 28, 30 which are not connected by bolts 36, and the length of the columns 38 is normally adjusted in such a manner that the last-mentioned frame sides are vertically separated by a narrow gap. The weight of the gristmill including the bin 2, the rollers 12, the motor 72, the pump 14, and the weight of the material being processed in the mill thus are transmitted by the bar 50 to the columns 38, and thereby to the foundation frame 30. The load applied to the terminal bar portions 52 tends to deform the bar 50 in such a manner that the central bar portion is flexed upward, whereas the central bar portion moves downward because of the resilient recovery of the bar when the bar is relieved of the applied weight.

The central portion of the bar 50 carries a portion of the control assembly 68 which is not duplicated in the nonillustrated symmetrical half of the structure partly shown in FIG. 3. An annular clamp 60 on the bar 50 has a radial lug 62 in which a threaded abutment pin 64 is threadedly received. The effective length of the pin 64 can be adjusted by turning the pin, and the pin can be locked in the adjusted position by means of a nut 66. The pin cooperates with a normally open switch 67 best seen in FIG. 2.

The switch is mounted on the upright support frame 26 and is provided with a rocker 76, one arm 78 of which carries a roller 80 axially aligned with the pin 64. Another arm 82 of the rocker presses against a push button 84 of the switch 67 if the rocker is pivoted clockwise from the position of FIG. 3 by the pin 64.

The afore-described apparatus operates as follows:

The resiliency of the bar 50 is chosen in such a manner that the bar is deflected from the position shown in FIG. 3 when the bin is filled with a batch of malt, whereby the pin 64 engages the rocker 78, and the energizing circuit of the motor 72 is closed by the switch 67. When the batch of malt is consumed, the bar 50 straightens sufficiently to withdraw the pin 64 until the switch 67 is opened to stop the motor 72.

It will be appreciated that the switch 67 may further be provided with a set of contacts which start a timing switch as soon as the motor 72 is stopped, the timing switch opening and closing solenoid valves, energizing and deenergizing the pump 14, and intermittently energizing the motor 72 as needed to provide washing water for the bin 2 and otherwise make the gristmill ready for the next batch of malt in an automatic cycle of operations known in themselves, of which the stopping of the rollers 12, is but the most important single step.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

1. In a gristmill having a foundation, a support including a mill housing mounted on said foundation, a malt bin mounted on said support, malt feeding means for feeding malt from said bin to said housing, crushing rollers in said housing, drive means for rotating said rollers and for thereby crushing the fed malt, and drive control means for starting and stopping said drive means, the improvement in the drive control means comprising:

(a) resilient load transmitting means interposed between said support and said foundation for transmitting a portion of the weight of said support and of mass supported thereby to said foundation,

.4 (1) said load transmitting means including a load transmitting member resiliently deformable in response to the transmitted weight; and

(b) control operating means engageable by the deformed load transmitting member and operatively connected to said drive control means for respectively rotating and stopping said rollers in response to the deformation of said load transmitting member under an applied weight and in response to the resilient recovery of said member when relieved of the applied weight.

2. In a mill as set forth in claim 1, means for feeding water to said housing, for mixing the fed water with the crushed malt so as to form a mash, and for withdrawing said mash from said housing, the weight of said malt, of said water, and of said mash, while in said housing and in said bin, being transmitted by said load transmitting means to said foundation.

3. In a mill a set forth in claim 1, said load transmitting member being an elongated bar member, two longitudinally spaced portions of said bar member being secured to said support, and a portion of said bar member intermediate said spaced portions engaging said control operating means.

4. In a mill as set forth in claim 3, said bar member being elongated in a horizontally extending direction.

5. In a mill as set forth in claim 3, said foundation including two column members respectively engaging parts of said intermediate portion substantially equidistant from said spaced portions respectively.

6. In a mill as set forth in claim 3, said control operating means including two abuttingly engageable control operating members, one of said members being mounted on said intermediate portion of said bar member, and the other control operating member being mounted on said support.

7. In a mill as set forth in claim 6, said drive means including an electric motor, said drive control means including a switch in circuit with said motor, and one of said control operating members operating said switch.

8. In a mill as set forth in claim 3, said support including a frame having two horizontally spaced, opposite sides, rigid load transmitting means interposed between one of said sides and said foundation, said resilient load transmitting means being interposed between the other one of said sides and said foundation.

9. In a mill as set forth in claim 8, the direction of elongation of said bar member being substantially parallel to said sides.

References Cited UNITED STATES PATENTS 419,750 1/18'90 Clink 24136 427,483 5/1890 Sargent 24136 X 924,678 6/1909 Leake 241- XR 2,217,568 10/1940 Shirley 24136 3,350,018 10/1967 Harris 24136 X FOREIGN PATENTS 1,092,420 11/ 1960 Germany.

ROBERT C. RIORDON, Primary Examiner D. G. KELLY, Assistant Examiner U.S. Cl. X.R. 

